Transition metal complexes with thiosemicarbazide-based ligands. Part 47. Synthesis, physicochemical and voltammetric characterization of iron(III) complexes with pyridoxal semi-, thiosemi- and S-methylisothiosemicarbazones

Abstract

The reaction of warm EtOH solutions of FeX3·nH 2O (X = Cl, NO3) with tridentate ONX (X = O, S, N) pyridoxal semi-, thiosemi- and S-methylisothiosemicabazones (H2L 1, H2L2, H2L3, respectively) yielded high-spin octahedral mono- and bis(ligand) complexes of the formula [Fe(H2L1-3)Cl2(H2O)]Cl, [Fe(HL1,2]Cl·nH2O and [Fe(H2L 3)(HL3)](NO3)2·H 2O. The compounds were characterized by elemental analysis, conductometric and magnetochemical measurements. IR and UV-Vis spectra. Besides, a detailed voltammetric study of the complexes was carried out in DMF solution in the presence of several supporting electrolytes, to characterize the nature of the electrode processes and solution equilibria.